DETROIT (AP) — The U.S. government is investigating whether General Motors should add about 312,000 vehicles to a 2015 recall for headlights that can suddenly go dark. The National Highway Traffic Safety Administration says 128 owners have complained that low-beam lights can fail. The investigation covers the 2005 and 2009 Buick Lacrosse; the 2006 and 2007 Chevrolet TrailBlazer, GMC Envoy and Buick Rainier; the 2006-2008 Isuzu Ascender and Saab 9-7X; and the 2007 Pontiac Grand Prix.Read more on NewsOK.com